Low-level light therapy has become an alternative to many types of treatments previously thought to be best-effected by high-energy methods, such as those using lasers, flashlamps, etc. For example, photodynamic therapies, lasers and other high-energy light treatments were believe to be an effective treatment method to reduce or eliminate the skin disorders associated with the activity of sebaceous oil glands, hair growth, wound healing and treating dermatological conditions, such as the reduction of wrinkles and fine lines, scar removal, etc.
Those skilled in the art speculate that oxidative stress and mitochondrial function or dysfunction are involved in the pathogenesis of numerous retinal, visual pathway, and optic nerve diseases, including age-related macular degeneration, diabetic retinopathy, as well as Leber's hereditary optic neuropathy and many other disorders of the visual pathway. Decreasing mitochondrial function has also been asserted to be related to methanol intoxication. It has been noted that Methanol intoxication produces toxic injury to the retina and optic nerve, frequently resulting in blindness. A toxic exposure to methanol may result in the development of formic acidosis, metabolic acidosis, visual toxicity, coma, and, in extreme cases, death. Visual impairment may develop between 18 and 48 hours after methanol ingestion. Symptoms may range from misty or blurred vision to complete blindness. Both acute and chronic methanol exposure have been shown to produce retinal dysfunction and optic nerve damage clinically. Other chemical agents can produce similar disorders
Formic acid is a toxic metabolite responsible for the retinal and optic nerve toxicity produced in methanol intoxication. Formic acid is a known mitochondrial toxin that may inhibit cytochrome c oxidase, the terminal enzyme of the mitochondrial electron transport chain of all eukaryotes. Cytochrome oxidase is an important energy-generating enzyme critical for the proper functioning of almost all cells, especially those of highly oxidative organs, including the retina and brain.
Photomodulation using narrowband, multichromatic light using low-energy sources, such as light-emitting diode (LED) arrays have been shown to accelerate wound healing, improve recovery from ischemic injury in the heart, and improve many skin-related disorders as illustrated in U.S. Pat. No. 6,663,659 (McDaniel) which is hereby incorporated by reference in its entirety. Further, at the cellular level, the use of light at low energy fluences may generate significant biological effects, including cellular proliferation, collagen synthesis, and the release of growth factors from cells, alteration of gene expression and even repair of DNA damage.
Studies have demonstrated that LED photomodulation at 660 nm (<4 J/cm2) may stimulate cellular proliferation in cultured cells and significantly improves wound healing. However, despite widespread clinical application, the mechanisms responsible for the beneficial actions of photomodulation are not fully understood. A possible explanation for this may be that mitochondrial cytochromes could act as photoacceptors for light energy; and, further, other receptors may act as mediators for the biological effects of this light.